The Royal Mail made a £3 million profit in the first half of the financial year -the first time it has been in the black at this stage for five years.

But despite the good news today, chairman, Allan Leighton, said there was a long way to go before it achieved sustainable profitability.

The company, still clearing a backlog of mail following wildcat strikes by postal workers, said its day-to-day operations made a £55 million profit compared with a £147 million loss a year ago.

The Communication Workers' Union called on the Royal Mail to halt the threat of thousands of job losses following news of the profit.

Union general secretary, Billy Hayes, said today's figures proved the business was in a much better financial position than the Royal Mail had pretended over the last three years.

"It is time to start providing the public with the postal service we used to have in this country. For a start, the company should drop its threat to the livelihoods of 30,000 postal workers," he said.

The financial figures covered the six months to September, before the unofficial strikes which are believed to have cost Royal Mail millions of pounds.

The Royal Mail made a £542 million loss in the first half of last year but has benefited from a 1p rise in stamp prices in May.